Homebrew_PCBs

Hi Stefan,

I tried baking in the oven and that is an insane process... Then I
tried to use a 'flat grill' and I did get a great transfer in one
area but hardly anything in another. The root cause seems to be what
you said about 'flatness'. I bet I wolud never have any of the
problems if my board was smaller than my iron. I'll read thru your
psots and maybe thre is something I missed.

What paper are you using? I am using HP high gloss laser paper.


Happy New Year! Mike


--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:

> On Thu, 01 Jan 2004 03:33:46 -0000, mikezcnc <marabu@c...> wrote:
>
> > Stefan,
> >
> > Thank you for such an extensive description of your process. You

nailed

> > my problems: lousy printer, one iron only and the rest. I clean

my board

> > with acetone (to remove leftovers and I have always plenty of

those,

> > don't ask why...), then water with dishwasher soap, tehn

sandpaper 600,

> > then brillo pad with detergent. Then all is well flushed with

water.

> >
> > Your process is interesting, but it takes s much time toand full
> > attention. I am for the idea of Ron Peopeil: set it and forget

it. Which

> > brings me to another idea: chicken grill, just kidding. I agree

with your

> > supposition that higher temperature is more forgiving than lower

and that

> > two high pressure is not good for narrow traces.
> >
> > I ahve one of those $2 grills for hamburgers but their footpriny

is just

> > too small.
> >
> > The problem with iron is that I suspect that temperature is not

evenly

> > distributeed and therefore it must be set higher to compensate

for the

> > uneveness. However, that higher (than neccessary temperature -
> > someone mentioned 130 being needed for fusing..) causes problems

in areas

> > with widened lines due to pressure. In other words the correct

pressure

> > and slightly higher temperature in one area becomes correct

pressure and

> > incorrect temperature in another, due to a temperature gradient

within a

> > PCB. My next trial will be a Singer iron press that I picked up

from a

> > garage sale 2 summers ago for this convenient moment of being

able to

> > laminate PCBs... Right now I am baking that PCB in an oven after

I

> > finished pizza and New Year's ham... Mike
> >
> >
>
> Hi
>
> In some dark corner i should have a iron press, maybe i try that..
>
> to the press ideas:
>
> PCBs are not compeltely flat ask the milling guys.
> If you have a flat plate (heated and press it against the pcb
> i doubt you get a even distribution of the pressure.
>
>
> you would need a flexible plate with flexible backing, which again

leaves

> you
> with much harder pressed edges.
>
>
> I can only speak from experience, my iron seems to be flat, but if

i only

> press it on flat (without moving around with the curved edge)
> there are always areas that don't adhere.
>
>
> I will measure for you the distribution of the heat in an iron.
> But i strongly suspect that there is no more than 2° difference.
> (in a solid aluminium iron, not stainless steel sheetmetal coated

bottom)

>
>
> I don't really experience your problems, i get fairly good results
> in a wide pressure range (and i suspect also in a wide temp. range)
>
> Stefan